Due to its characteristics of being easily applicable to various products and electrical properties such as a high energy density, a secondary battery is not only commonly applied to a portable device, but universally applied to an electric vehicle (EV), a hybrid vehicle (HV), or an energy storage system that is propelled by an electric motor. This secondary battery is gaining attention for its primary advantage of remarkably reducing the use of fossil fuels and not generating by-products from the use of energy, making it a new eco-friendly and energy efficient source of energy.
A battery pack for use in electric vehicles has a structure consisting of a plurality of cell assemblies connected in series, each cell assembly including a plurality of unit cells, to obtain high power. Also, the unit cell includes a cathode current collector and an anode current collector, a separator, an active material, and an electrolyte solution, and allows repeated charging and discharging by electrochemical reactions between the components.
In addition to this basic structure, the battery pack further includes a battery management system (BMS) to monitor and control a state of a secondary battery by applying an algorithm for control of power supply to a driving load such as a motor, measurement of electrical characteristic values such as current or voltage, charge/discharge control, voltage equalization control, state of charge (SOC) estimation, and the like.
Recently, with the increasing need for a high-capacity structure as well as utilization as an energy storage source, the demand for a battery pack of a multi-module structure in which a plurality of battery modules including a plurality of batteries connected in series and/or in parallel are assembled, is also increasing.
Because the battery pack of the multi-module structure includes a plurality of battery cells, there is a limitation in controlling the charge/discharge state of all the battery cells using a single BMS. Accordingly, a recent technology has been introduced in which a BMS is provided to each battery module included in the battery pack, any one of the BMSs is designated as a master BMS, and the remaining BMSs are designated as slave BMS, such that the charge and discharge of each battery module is controlled in a master-slave mode.
The slave BMS is in a sleep state in normal condition and wakes up from the sleep state by a control signal from the master BMS. The control signal may be transmitted via various communication networks, and generally a serial communication network is mainly used. The serial communication network has advantages of being easy to implement a communication structure, good signal transmission characteristics, and making use of an existing communication line, resulting in remarkable cost reduction.
The serial communication network has a connection architecture in which a receiver receiving a signal becomes a transmitter and delivers the signal to another adjacent receiver connected thereto by a relay scheme. Thus, between each BMS, an output connector for outputting a signal and an input connector for inputting a signal are separately provided and connected to each other.
FIG. 1 is a diagram illustrating an example of a configuration of a communication network according to a related art.
Referring to FIG. 1, it can be seen that computer systems 10, 20, and 30 corresponding to communication terminals constitutes a communication network. As shown in FIG. 1, it can be seen that, to construct a serial communication network, input parts 16, 26, and 36 and output parts 18, 28, and 38 included in each computer system 10, 20, and 30 are provided separately from each other and connected to each other.
However, when constructing the serial communication network in this way, if the shape of the input part connector is not clearly distinguished from the shape of the output part connector, an operator may get confused. Also, manufacturing an input part connector and an output part connector separately in different shapes will be one factor of increasing a production cost. Therefore, there is a need for a communication terminal with compatible input and output connectors when constructing a serial communication network.